The studies evaluated denosumab and a sclerostin antibody. These antibodies target key proteins responsible for the regulation of bone destruction and formation. The research was presented at the American Society for Bone and Mineral Research.
Denosumab is an investigational antibody that targets RANK Ligand, a key protein that is the primary mediator of cells which resorb or break down bone. Denosumab is the first therapy in late stage development that targets RANK Ligand.
Results from analysis of an ongoing study, show that patients experience an improvement not only in bone mineral density (BMD) but also in parameters of hip structural analysis (HSA), a technique that estimates geometric properties of bone strength. In the study, patients were found to have increased cortical thickness when administered with alendronate and denosumab.
Amgen commented that the results were consistent with previous reports highlighting the effects of denosumab at highly cortical sites of the cortical bone and the dense outer shell of the skeleton.
“Increasing thickness at highly cortical sites is an effective way to improve bone strength and mechanical integrity of the skeleton,” said Thomas Beck, associate professor at the Johns Hopkins University. “These observations support the potential of targeting RANK Ligand to improve bone structural strength.”
Amgen is also reporting on preclinical data for denosumab at the meeting. In this study, designed to evaluate the effects of denosumab administration in aged primates after estrogen depletion, researchers found that long-term denosumab administration is associated with increases in the mass and density of cancellous and cortical bone.
In the osteoporosis setting, denosumab is being investigated as a twice-yearly injection and appears well-tolerated in clinical trials to date. Occurrence of adverse events in a phase II trial was similar among the all the treated groups with the exception of dyspepsia, which was more common among those receiving alendronate. The most common adverse events among all groups were upper respiratory infection, joint pain, sore throat, back pain, and headache.